Field of the Invention
The application relates in general to a CIS structure (CMOS Image Sensor), and in particular, to a CIS structure having a reflective structure.
Description of the Related Art
Conventional optoelectronic products, such as digital cameras, or mobile phones capable of capturing images, have become more and more popular, the functional demand for image sensor devices has increased accordingly. An image sensor device is used for receiving a light signal and converting the light signal into an electronic signal. After generating and processing the electronic signal, a digital image is produced. In general, image sensor devices can be categorized into two main types: one is a charge coupled device (CCD), and the other is a complementary metal oxide semiconductor (CMOS) device.
The image sensor device typically comprises a pixel array. Each pixel in the pixel array includes a photodiode that produces a signal corresponding to the intensity of light impinging. In conventional image sensor devices, a micro lens array coupled with a color filter array (translucent structure) is correspondingly disposed above the pixel array of the image sensor device. The color filter array allows the pixels to collect light with specified wavelengths.
However, despite the use of the micro lens array, a large amount of incident light may not be efficiently directed to the photodiode. As a result, the photosensitivity of the image sensor device may be reduced.